/Engine/Source/Editor/UnrealEd/Public/Subsystems/AssetEditorSubsystem.h
Notify the asset editor manager that an asset editor is being opened and before widgets are constructed
void NotifyEditorOpeningPreWidgets ( const [TArray](API\Runtime\Core\Containers\TArray)< [UObject](API\Runtime\CoreUObject\UObject\UObject) * > & Assets, [IAssetEditorInstance](API\Editor\UnrealEd\Subsystems\IAssetEditorInstance) * Instance )